The new HALYARD MICROCOOL Breathable High Performance Surgical Gown is the result of years of research to make MICROCOOL more cool and protective than ever. Kimberly-Clark has a long heritage of medical fabric leadership, with over 650 US and international patents for advanced non-woven fabrics. Patented Microporous Fabric: Soft spunbound outer layer; Proprietary breathable fabric; SMS fabric inner liner layer. HALYARD MICROCOOL Gowns meet the AAMI Level 4 liquid barrier standard. The Association for the Advancement of Medical Instrumentation (AAMI) developed the liquid barrier standard to assist healthcare personnel in the selection and use of surgical gowns, drapes and other protective apparel. MICROCOOL Gowns are Level 4, the highest barrier protection rating available for gowns. HALYARD MICROCOOL Breathable High Performance Surgical Gowns provide Level 4 liquid barrier in zones A, B, and C. For surgical gowns, the critical zones are, at a minimum, the front area of the gown from chest to knees (area A) and the sleeves from the cuff to above the elbow (area B). The standard requires that the entire front of a surgical gown (Areas A, B, and C) provide a liquid barrier of at least Level 1. The back of the gown (area D) may be non-protective.